Generally, vehicles can be equipped with collision avoidance and warning systems for predicting potential collisions with external objects, such as another vehicle, a pedestrian, or a stationary object. These systems typically include driver interface and initiate countermeasures (e.g., enunciate driver alerts, enact vehicle dynamic actions, and deploy occupant protection/restraint devices) in order to anticipate crash scenarios and eliminate or mitigate the impact of those crashes. An example of a system where predicting a collision is desirable is an adaptive cruise control systems that generally tracks multiple leading vehicles and automatically controls both the speed and distance of the host vehicle.
Some vehicle avoidance systems generally require one or more object detection sensors for tracking one or more targets within a field of view. Some such target tracking systems can require yaw rate sensors for tracking a motion path of the host vehicle, and relatively complex and expensive detection sensors to acquire the range, range rate, azimuth angle to the detected objects. Other vehicle avoidance systems generally have object detection sensors that monitor markers on the roadway. Object detection sensors for requiring such data can be costly and require intensive calculations, analysis, and/or processing when analyzing the data, which adversely affects the processing or reaction time of the vehicle target tracking system or require the roadway to have markers.
Other collision avoidance systems view targets in the field of view by determining the crossing location or a miss distance. One such approach is disclosed in U.S. Pat. No. 6,615,138, entitled “COLLISION DETECTION SYSTEM AND METHOD OF ESTIMATING MISS DISTANCE EMPLOYING CURVE FITTING,” the entire disclosure of which is hereby incorporated herein by reference. Another approach is disclosed in U.S. Pat. No. 7,016,782, entitled “COLLISION DETECTION SYSTEM AND METHOD OF ESTIMATING MISS DISTANCE,” the entire disclosure of which is hereby incorporated herein by reference. Another approach is disclosed in U.S. Patent Application Publication No. 2005/0197770, entitled “COLLISION DETECTION SYSTEM AND METHOD OF ESTIMATING TARGET CROSSING LOCATION,” the entire disclosure of which is hereby incorporated herein by reference. While the aforementioned approaches use at least one sensor to determine an object in a field of view, the above systems can create a situation where, due to the data being collected and the analysis, calculations, and/or processing of the data, the processing or reaction time of the system is longer than desired. Further, in some situations, the above approaches can create false identifications or false alarms where an object is within the field of view, and the system identifies this object as being in the in-path area, which enables a collision warning and/or an avoidance countermeasure, but the vehicle would not contact the object due to the vehicle's range of motion.